Deutsche Bank’s CEO, Christian Sewing, has also canceled plans to attend the summit, a source close to the matter said on Friday.

Foreign Minister Heiko Maas, who had been trying to rebuild strained ties with the kingdom before Khashoggi disappeared on Oct. 2, called the situation “unacceptable”. He told reporters that Berlin would draw its consequences once Riyadh provided a statement on the issue.

Khashoggi, a U.S. resident and Washington Post columnist critical of Riyadh’s policies, went missing after entering the Saudi consulate in Istanbul. Turkey believes he was murdered and his body removed. Saudi Arabia has denied that.

Airbus said Hoke would not attend the Saudi investment conference given a new guideline ordering executives to abstain from high profile engagements there, but the company would not break off contact with the Gulf kingdom.

“We believe it is important to maintain engagement and dialogue in a country which hosts about 1,000 of our employees,” a spokesman said.

The investment summit, dubbed Davos in the Desert, in Riyadh typically attracts executives from some of the world’s largest companies and media organizations.

Many of those slated to attend, including U.S. Treasury Secretary Steven Mnuchin, have canceled their participation, but the Saudis have said they plan to move forward with the conference, scheduled for Oct. 23-25.

Siemens CEO Joe Kaeser has not yet announced whether he will attend.

Opposition lawmakers are calling on Berlin to halt arms deliveries to the kingdom, the second largest customer of German weapons this year behind Algeria.

Germany approved a total of 416 million euros in arms sales to Saudi Arabia in the first nine months of 2018, economics ministry data showed.

Maas told reporters: “If the rumors should prove true, it’s not only shocking, it’s unacceptable. We believe that it is about time now for the statement that Saudi Arabia has promised.”

He said Germany would respond promptly after the statement, and in coordination with its European allies.

The German government decides on any arms exports individually, with a particular eye on human rights in the receiving country, a government spokeswoman said.

Annalena Baerbock, leader of the left-leaning Greens party, called for all German arms deliveries to Saudi Arabia to “be put on ice immediately” and urged Kaeser and other executives to cancel their participation in the conference.